Method of and system for efficient use of telecommunication networks

ABSTRACT

A system for use of a telecommunications voice network includes a communication node local to a calling location for acquiring calling and called party identification numbers and transmitting them to a central switching unit associated with a called location, through a transception channel independent of the telecommunications voice network. Further provided is a central switching unit for interrogating the called location to obtain a call supervision status thereof. Also provided is an apparatus for completing a first phonecall from the switching unit to the called location if the call supervision status is that of an answer, and for originating a second phonecall through the telecommunications network to the calling location. Teleconferencing of the first and second phonecalls then occurs. Further provided is an apparatus for providing an uncompleted call status signal to the central switching unit if the call status is that of a no answer or busy. The calling party is then appropriately advised. Upon termination of the second phonecall an answer supervision signal is sent by the local node to the central switching unit.

APPLICATION FOR LETTERS PATENT

This is a continuation of U.S. Ser. No. 09/009,007, filed Jan. 16, 1998,now U.S. Pat. No. 6,078,654, which is a continuation of U.S. Ser. No.08/728,670, filed Oct. 10, 1996, now U.S. Pat. No. 5,710,809, which is acontinuation of U.S. Ser. No. 08/320,269, filed Oct. 11, 1994, nowabandoned, each of which is hereby incorporated by reference.

Be it known that I, Alexander Mashinsky, a resident of the State of NewYork and citizen of the Republic of Israel, have invented a certain newand useful improvement in a Method of and System for Efficient Use ofTelecommunication Voice Networks, of which the following is aSpecification:

BACKGROUND OF THE INVENTION

A long standing problem in the area of international telecommunicationsand, more particularly, in the area of initiating and completinginternational phonecalls over public switched service voice networks hasbeen that a considerable portion of the so-called system time, that is,the period between initiation of a phonecall and either completionthereof or determination that the call cannot be completed (because of ano answer or busy signal) is non-billable in nature. For example,billing-protocols, as they have evolved over time, both in the UnitedStates and abroad, only permit billing to the ultimate customer for theperiod between call completion and call termination as perceived by theultimate customer. In other words, under such established billingprotocols, the ultimate customer (as opposed to an intermediary such asa hotel or aggregator) cannot be charged for the system time required toring the called location to determine if the call can be completed.Further, such phonecalls do not permit billing for the so-calleddisconnect time, that being the time between the termination of thephonecall as perceived by the caller and the actual stand down or resettime by the public switched service network.

The prior art use of system time in such a non-productive fashion hasalso operated to limit total usable system capacity in areas wheretrunk, channel or bandwidth capacity is finite, as in third worldsituations and in satellite transception.

To minimize such non-billable system time and, as well, to effect otheradvantages, the development of so-called call back technology, alsoknown as reverse direction phonecalling, has developed. In callbacktechnology, a so-called network control module induces a callback from acentral switching station associated with the called location. Thiscall-back procedure has the advantage not only of reducing unbillablesystem time inasmuch as a callback will not be initiated if the calledlocation is unreachable but, as well, to effect considerable saving incall cost by virtue of the fact that call cost from Location A toLocation B typically does not equal call cost from Location B toLocation A, this being particularly the case in international phonecommunications.

The technology of point-to-point reverse direction phonecalling, bothfor purposes of minimizing system time and for purposes of minimizingcall cost based upon the directionality of the call, is well developedin the art, as is exemplified by U.S. Pat. No. 5,027,387 (1991) to Moll,entitled Reverse Direction Calling System.

Such reverse direction calling technology has, however, not beenuniversally available. For example, in a hotel environment, a guest atthe hotel has no means of answering a callback directly since thecallback must be received by an operator that must know in advance whothe call is for and where to transfer it to. This difficulty, plus otherfactors relative to billing procedures in hotels, has prevented mostmajor hotels from employing international callback services. Similarproblems are encountered by other large facilities such as hospitals,industrial installations, governmental sites and telephone companiesthemselves.

A further limitation in the art of callback technology has existed inthe area of teleconferencing of international calls in which, forreasons of reduction of system time use and avoidance of phone chargesby high priced national phone companies, it is desirable to route acall, from a first foreign country to a second foreign country, througha third foreign country (known as transit country) typically the UnitedStates, Canada or United Kingdom, to avoid the typically highcountry-to-country charge between the first and second countries. Forexample, in situations where call supervision exists, it is generallycost-effective to reconfigure what would otherwise be a call fromCountry A to Country B into the form of teleconferencing of two separatecalls, namely, a call from Country C (typically the U.S.) to Country A,with a call from Country C to Country B. This procedure will, because ofthe high cost of calls originated from Country A, be less than the costof a direct dialed Country A to Country B phonecall. In other words,where all legs of the CA and CB phonecalls are completed, the total costof the teleconferenced CA and CB calls is less than the cost of thedirect dialed Country A to Country B cost would have been.

The problem, however, with such callback and teleconferencing procedureshas been that in situations where either or both the CA and CB legs ofthe teleconference cannot be completed because, for example, of a busyor no answer at Locations A or B, the provider of the internationalcallback service must absorb the cost of the system time associated withinterrogating locations in Countries A and B in attempting to completethe CA and CB legs of the phonecall. As such, the international reversecallback procedure can involve considerable losses to the callbackoperator which can only be recovered by increasing the price charged forcompleted calls.

Another problem in international callback that can increase cost to theoperator is that of reverse answer supervision after a call termination,or the lack thereof. That is, without a call completion signaltransmitted back from the calling location to the transit country switchafter call termination, it can-be difficult for the transit switch (inCountry C) to know when a call is finished. This issue can havedevastating consequences to the callback operator.

The instant invention provides a solution to the above problems and,additionally, provides a means by which hotels, and other similarlysituated establishments, can make use of international callbacktechnology and, further, can do so on a more profitable basis than hasbeen available to any prior user of such technology. The presentinvention also addresses problems of billing to intermediaries and endusers of callback facilities.

SUMMARY OF THE INVENTION

The present novel method of use of a public telecommunications voicenetwork (typically a public switched service network) includes the stepsof assigning a caller identification number to a calling location and ofassigning a called party identification number for the location to becalled. Thereafter, use is made of a transparent communications node,associated with the calling location, which transmits said caller andcalled party identification and security numbers to a central switchingunit in the nature of a digital tandem ISDN switch or private line dataservice which is associated with the called location. Said transmissionof caller and called party identification number to the centralswitching unit proceeds through a data signalling channel independent ofthe public telecommunications voice network. Said central switching unitis then employed to interrogate the called location to obtain the callsupervision status thereof. If said call status is that of an answer,said central switching unit will complete a first phonecall from saidunit to the called location and will originate a second phonecallthrough the telecommunications network to the calling location. Uponcompletion of both phonecalls, they are teleconferenced, thereby placingthe calling and called parties in communication with each other.However, if said call status at the called location is that of a noanswer or busy, an uncompleted call status signal is provided to thecentral switching unit. Thereafter, the central switching unit mayeither transmit a call status signal through said independent signallingchannel to the local communications node to inform the calling locationthat the call cannot be completed or, alternatively, the centralswitching unit may not send any status signal whatsoever to the localcommunications node. Therein, a predetermined interval of silence fromthe central switching unit will be interpreted by the localcommunications node to mean that the call could not be completed. Anappropriate advisory will be sent to the calling party. Upon terminationof the second phonecall, an answer supervision signal is sent by thelocal node to the central switching unit.

It is, accordingly, an object of the present invention to provide animproved method and system of telecommunications network use which willoperate to reduce system time and operator cost associated withteleconferencing of international calls involving at least one reversedirection phonecall.

It is another object to provide a system of the above type that willincrease the efficiency of use of telecommunication resources.

It is a further object to provide a method which will reduce the cost ofcollect and person-to-person long distance phonecalls.

It is a yet further object to provide a system of the above type usablein connection with multi-trunk switching.

It is a still further object to provide an improved method oftelecommunication network use which will enlarge the potentialapplication of reverse direction telephone calling to areas, such ashotel and telephone company use, in which it has not heretofore beenusable.

It is another object to provide a system of the above type havingreverse answer detection after call termination.

The above and yet other objects and advantages of the present inventionwill become apparent from the hereinafter set forth Brief Description ofthe Drawings, Detailed Description of the Invention and Claims appendedherewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual block diagram indicating the principles ofoperation of the inventive method.

FIG. 2 is a flowchart reflecting the programming of a first embodimentof the inventive system and method.

FIG. 3 is a flowchart reflecting the programming of a second embodimentof the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the system block diagram view of FIG. 1 there is, inconceptual form, shown a telecommunications network 10 which may,without limitation, include a public switched service network such asthat of the well known public carriers, e.g., AT&T, MCI, and SPRINT or,alternatively, may, comprise any of a number of private voice/faxtelecommunications network.

Illustrated as the triangular symbol to the left of FIG. 1 is a callinglocation 12 and, in the triangular symbol to the right of FIG. 1 isrepresented a called location 14.

The square block to the upper left of FIG. 1 is representative of atransparent telecommunications node 16 which is local, e.g., privatelined, to the calling location 12. Such a unit is commercially availablefrom Voice Smart, Inc., Fort Lee, N.J., under the trademark HOTEL LOCALNODE. Its various capabilities include means to induce a callback from atelephone central switching location. Node 16 is interfacable with aPABX at the user location.

The block to the lower left of FIG. 1 is representative of a first datamessage means 18 for receiving information from or providing informationto local node 16. Data message means 18 also, as is more fully set forthbelow, provides information to data signalling channel 20 and is able toreceive information therefrom. Data message means 18 is preferablyprovided with means to verify the identity and/or authority of callinglocation 12. Node 16 and means 18 may comprise the.same physical unit.

It is noted that transception channel 20 represents a communication modewhich is external to telecommunications voice network 10. That is,transception channel 20 may take any one of a variety of formsincluding, without limitation, ISDN switch packet message means, telex,TWX, leased data lines, shared leased data lines, statisticalmultiplexing of data lines, data or MF over voice (DOV), Satellite(VSAT), PCN, Radio, DTMF and the so-called public packet network.

The block to the upper right of FIG. 1 is representative of a centralswitching unit 22 which is associated with the called location 14.However, the central switching unit 22 may be physically located at adistance on the order of thousand of miles from location 14. Centralswitching unit 22 will typically be a device in the nature of a digitaltandem ISDN switch, also known as a VX switch. Digital tandem ISDNswitches are known in the art and are available from such sources asVoice Smart, Inc., Fort Lee, N.J. under the names of VX SYSTEM 4 and VXSYSTEM 24. In simplest terms, central switching unit 22 is a PABXcapable of initiating a reverse direction phonecall when so instructedby a so-called automated attendant activated by the node 16 associatedwith the calling location 12, as is Taught in U.S. Pat. No. 4,313,036Jabara and in Moll supra.

The square at the lower right of FIG. 1 represents a second data messagemeans 24, similar to said first data message means 18, the function ofwhich is to facilitate transfer of information between said centralswitching unit 22 and said signalling channel 20. Second data means andunit 22 may comprise the same physical unit.

With respect to the method of use and operation of thetelecommunications components shown in FIG. 1, the instant methodentails the assignment by node 16 of a caller identification number tocalling location 12. Similarly, there is assigned a called partyidentification number (typically the called telephone number) for thecalled location 14. Thereby, a phonecall 26 originating from callerlocation 12 is acquired at local node 16 which stores data correspondingto the caller identification number and the called party identificationnumber. Local node 16 then refers to a database which advises it whetherto attempt to route the call through channel 20 or whether to employ theconventional communications network 10. If a decision is made to employthe external channel 20, the calling and called party identificationnumbers, as well as suitable access and security codes, are transmitted,via link 28 to data message means 18.

Data message means 18 comprises digital data processing means in thenature of a 486 type 66 megahertz computer having at least 16 megabytesof memory, a one gig drive, at least one external mode, and an X.25gateway card. its software includes X.25 connectivity software, anddigicard hardware. It will typically operate in a UNIX environment. Assuch, data message means 18 will accept an input over any publicswitched service network and will provide an output to any ISDNpacket-switched network such as those embodiments of signalling channel20 set forth above.

The caller location information is then provided over link 30 to saidexternal channel 20 which in turn furnishes such information over link32 to second data message means 24 associated with the called location14. The requisite calling and called party identification information isthen provided over link 34 to said central switching unit 22 which,using line 36, interrogates called location 14 with a first phonecall37, which will send back to central switching unit 22 a call supervisionstatus signal 38 which will inform central switching unit 22 as tocondition of the called location 14, i.e., a busy condition, a noanswer, or a call completion. If said call supervision status is that ofan answer, a callback 40 to the calling party is initiated by centralswitching unit 22, using communications network 10. Thereafter callback40 proceeds as would a normal phonecall, passing through local node 16and, therefrom, to the calling location 12. Thereupon, said secondphonecall 38 and first phonecall 37 are teleconferenced by centralswitching unit 22, thusly enabling the calling and called parties tocommunicate.

In the event that central switching unit 22 receives from the calledlocation 14 a busy or no answer condition, there may be provided anuncompleted call signal 42 to data message means 24 which is transferredtherefrom through signalling channel 20, to first data message means 18and therefrom to local node 16. Thereupon a “called party unavailable,”busy signal or other message 44 will be communicated by local node 16 tocalling location 12.

It is to be appreciated that, in the alternative to the use of callstatus signal 42, local node 16 may simply be programmed to communicatethe “called party unavailable” message 44 to the calling location 12 ifit does not receive an incoming call from telecommunications network 10within a predetermined period. In this scenario, it is not necessary forsignal 42 to be transmitted back from central switching unit 22, throughtransception channel 22, and to local node 16.

After call termination, node 16 will generate a reverse answersupervision signal 47 to advise unit 22 that calling location 12 hashang-up. This terminates the billing process. Said signal 47 may passover either network 10 or channel 20.

As indicated by dotted line 46, it is possible to integrate thefunctions of local node 16 and first data message means 18 such thatcommunications from the calling location to the data signalling channel20 would occur in a more direct fashion.

Through the above-described method and system, the system time and,thereby, the cost typically incurred by the calling party (or, in thecase of a hotel setting, by the hotel itself) in connection with theabove-described telecommunication system costs associated with busy andno answer signals is substantially avoided in that use will not be madeof the public switched service or other communications network where thefirst call 37 is not completed. Accordingly, the user will pay only forcompleted calls and will incur substantially no cost for uncompletedcalls. Also the benefits of reverse direction dialing is fullyaccomplished in the above system in that, where called location 14 is aforeign country or is in an earlier (more westerly) time zone thancalled location 12, the applicable call rate protocol will generallydictate that savings will be effected if the phonecall is initiated fromthe United States to the foreign country or, in the case of a domesticcall, from the more easterly time zone to the more westerly time zone(except during those situations where the more easterly time zone iswithin a business day and the business day has not yet begun in theearlier time zone).

In addition to the above set forth advantages of the present method, itmay be utilized to effect savings in calling between one foreign countryand another foreign country as is discussed in the Background of theInvention above. More particularly, in this scenario, a calling location48 in a first foreign country wishes to place a call to the calledlocation 14 in a second foreign country. Rather than employ the localforeign phone company (known as the PTT) to call from locations 48 to14, call 50 is made to local node 16 which call includes caller,destination and security codes. The call is then processed in the samemanner as said call 26. If call 50 is completed to location 14, acallback 40/52 occurs from central switching unit 22 to local node 16 tothe calling location 48 over network 10, teleconferencing the callinglocation 48 in a first foreign country with the called location 14 in asecond foreign country, all without need to make significant use of thelocal phone company at location 48. If the central switching unit 22receives a busy or no answer from location 14, the calling location 48will receive a “called party not available” message similar to theabove-described message 44. Therein, none of the parties, namely, thecalling location 48, called party 14, or the operator of local node 16,will have incurred any significant cost by reason of the no answer orbusy signal. Thereby the cost of international communication issubstantially reduced by both avoiding the unbillable system time, abovedescribed in the Background of the Invention, and avoiding the highlocal foreign country phone company costs which occur in calls directlybetween countries external to the United States.

There is, with reference to FIG. 2, shown a flow diagram of thedecision-making process employed in the software associated with localnode 16. This software, more particularly, shows, in block 54 thereof,the interception of the call from location call 12 by local node 16. Asabove noted, node 16 will then use its database to determine whether ornot to accept the call for purposes of the present international callback method and system. If node 16 rejects the call, it will be routedto the local PTT as is indicated in block 56. However, if the call isaccepted, node 16 will then proceed to acquire the destination number,that is, the called party identification number for the called location12, as is indicated by block 58.

Therefrom said signal 28 (see FIG. 1), containing the calling and calledparty identification numbers will be communicated, via data messagemeans 18, external channel 20, and second data message means 24, to saidswitch 22, as is indicated in block 60. Switch 22 will then make adecision to accept or not to accept the incoming phonecall 34 (see FIG.1). If the decision is that of non-acceptance, which will manifestitself as an absence in feedback through channel 20 to local node 16,local node 16 will decide whether or not to terminate the callcompletely, to use a different network, or to use the PTT, as isindicated in block 61.

If the decision of switch 22 is to accept the incoming call, it willoriginate a call to the called location 14 and will monitor for ananswer, as is indicated by block 62. If no answer occurs, switch 22 willterminate call 14 and may either send a “no answer” signal to datamessage means 24 and therefrom through channel 20 to local node 16 (seeblock 64) or, alternatively, may send no return message whatsoever. Inthat embodiment, local node 16 is programmed to construe a no response,after a predetermined interval, e.g., forty-five seconds, from switch 22as a “no answer.” In either event, local node 16 will play a “busy” or“called party unavailable” type message to the calling party 12 as isindicated in block 66.

In the event that called party 14 answers the call originated fromswitch 22, it may employ channel 20 to advise node 16 that an answer hasoccurred, as is indicated in block 68 or, alternatively, may go directlyto block 70 and, thereby, make a direct connection from switch 22 tolocal node 16 using the public telecommunications network 10. Thereinthe call from switch 22 to call location 14 will be teleconferenced withthe call from switch 22, through network 10, to the local node 16 and,thereafter, to location 12 or 18. After call termination by callinglocation 10, the reverse supervision signal 47 is sent to unit 22 overeither network 10 or channel 20 (see block 72).

With reference to FIG. 3, there is shown a further embodiment of theinvention which differs from that described above only in the use ofblocks 63, 69 and 71 in lieu of said blocks 62, 68 and 70.

Therein, in block 63, unit or switch 22 simultaneously originates callsto node 16 and called location 14, while monitoring for an answer atlocation 14. Called location 12 is kept on hold by node 16 untillocation 14 answers and instruction 42 is received from unit 22 to node16 instructing it to complete call 40 to location 12 (see block 69). Ifan answer occurs, unit 22 completes the call 40 to calling location 12and conferences that call to the completed call at location 14, therebyconnecting the parties (see block 71).

While there has been shown and described the preferred embodiment of theinstant invention it is to be appreciated that the invention may beembodied otherwise than is herein specifically shown and described andthat, within said embodiment, certain changes may be made in the formand arrangement of the parts without departing from the underlying ideasor principles of this invention as set forth in the Claims appendedherewith.

Having thus described my invention what I claim as new, useful andnon-obvious and, accordingly, secure by Letters Patent of the UnitedStates is:
 1. A method of use of a telecommunication system including acalling telephone equipment, a telecommunication network and a calledtelephone equipment, comprising the steps of: (a) transmitting to acontrol location identification for the calling telephone equipment andthe called telephone equipment; (b) receiving at the control locationidentification for the calling telephone equipment and the calledtelephone equipment; (c) determining whether a call from the callinglocation to the called party access number should be connected via thetelecommunication network, the step of determining being carried out ina manner transparent to the calling party and the called party; and (d)connecting the call from the calling party access number to the calledparty access number via the telecommunication network, when the step ofdetermining results in a determination that the call should be connectedvia the telecommunication network.
 2. A method according to claim 1wherein the step of determining results in a determination that the callshould be connected via the telecommunications network when the calledlocation is available for taking an incoming call.
 3. A method accordingto claim 1 wherein the step of determining includes: (e) receiving astatus signal at said control location indicating if said called partyis available for taking an incoming phone call.
 4. A method according toclaim 1 wherein the step of connecting the call comprises the steps of:(f) in response to said status signal, initiating a first phone callfrom said control location to said called party identification numberand a second phone call from said control location to said calling partyidentification number; and (g) bridging said first and second phonecalls.
 5. A telecommunication system including a calling telephoneequipment, a telecommunication network and a called telephone equipment,including: (a) means for transmitting to a control locationidentification for the calling telephone equipment and the calledtelephone equipment; (b) means for receiving at the control locationidentification for the calling telephone equipment and the calledtelephone equipment; (c) means for determining whether a call from thecalling location to the called party access number should be connectedvia the telecommunication network in a manner transparent to the callingparty and the called party; and (d) means for connecting the call fromthe calling party access number to the called party access number viathe telecommunication network, when the step of determining results in adetermination that the call should be connected via thetelecommunication network.
 6. A method of use of a telecommunicationnetwork including a calling telephone equipment and a called telephoneequipment, comprising the steps of: (a) selecting a transmission pathconnecting a calling telephone equipment and a called telephoneequipment, the step of selecting being carried out in a mannertransparent to the calling party and the called party; (b) receiving ata control location identification for the calling telephone equipmentand the called telephone equipment; (c) determining whether a call fromthe calling location to the called party access number should beconnected via the selected transmission path, the step of determiningbeing carried out in a manner transparent to the calling party and thecalled party; and (d) connecting the call from the calling party accessnumber to the called party access number via the selected transmissionpath in a manner transparent to the calling party and the called party,when the step of determining results in a determination that the callshould be connected via the selected transmission path.
 7. A methodaccording to claim 6 including the further steps of: (e) receiving astatus signal at said control location indicating if said called partyis available for taking an incoming phone call; (f) in response to saidstatus signal, initiating a first phone call from said control locationto said called party identification number and a second phone call fromsaid control location to said calling party identification number; and(g) bridging said first and second phone calls.
 8. A method according toclaim 7 further comprising the step of completing the second phone callin response to receiving a further status signal indicating that thefirst phone call has been completed.
 9. A method according to claim 6wherein step (c) includes the step of evaluating whether said calledparty access number is available for taking an incoming phone call. 10.A telecommunication network including a calling telephone equipment anda called telephone equipment, including: (a) means for selecting atransmission path connecting a calling telephone equipment and a calledtelephone equipment in a manner transparent to the calling party and thecalled party; (b) a control location arranged to receive identificationfor the calling telephone equipment and the called telephone equipment;(c) means for determining whether a call from the calling location tothe called party access number should be connected via the selectedtransmission path in a manner transparent to the calling party and thecalled party; and (d) means for connecting the call from the callingparty access number to the called party access number via the selectedtransmission path in a manner transparent to the calling party and thecalled party, when the step of determining results in a determinationthat the call should be connected via the selected transmission path.